The tuatara ( Sphenodon punctatus) has been protected by law since 1895. The species has between 5 and 6 billion base pairs of DNA sequence, nearly twice that of humans. Although tuatara have preserved the morphological characteristics of their Mesozoic ancestors (240–230 million years ago), there is no evidence of a continuous fossil record to support this. This term is currently deprecated among paleontologists and evolutionary biologists. Tuatara are sometimes referred to as " living fossils", which has generated significant scientific debate. They are able to hear, although no external ear is present, and have unique features in their skeleton, some of them apparently evolutionarily retained from fish. They have two rows of teeth in the upper jaw overlapping one row on the lower jaw, which is unique among living species. Tuatara are greenish brown and grey, and measure up to 80 cm (31 in) from head to tail-tip and weigh up to 1.3 kg (2.9 lb) with a spiny crest along the back, especially pronounced in males. For this reason, tuatara are of interest in the study of the evolution of lizards and snakes, and for the reconstruction of the appearance and habits of the earliest diapsids, a group of amniote tetrapods that also includes dinosaurs (including birds) and crocodilians. Their closest living relatives are squamates (lizards and snakes). Rhynchocephalians originated during the Triassic (~250 million years ago), reached worldwide distribution and peak diversity during the Jurassic and, with the exception of tuatara, were extinct by 60 million years ago. The single extant species of tuatara is the only surviving member of its order. ![]() The name tuatara is derived from the Māori language and means "peaks on the back". Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. Tuatara ( Sphenodon punctatus) are reptiles endemic to New Zealand. Symbols may represent up to seven islands. Continued abuse of our services will cause your IP address to be blocked indefinitely.Current distribution of tuatara (in black): Circles represent the North Island tuatara, and squares the Brothers Island tuatara. Please fill out the CAPTCHA below and then click the button to indicate that you agree to these terms. If you wish to be unblocked, you must agree that you will take immediate steps to rectify this issue. If you do not understand what is causing this behavior, please contact us here. If you promise to stop (by clicking the Agree button below), we'll unblock your connection for now, but we will immediately re-block it if we detect additional bad behavior. Overusing our search engine with a very large number of searches in a very short amount of time.Using a badly configured (or badly written) browser add-on for blocking content.Running a "scraper" or "downloader" program that either does not identify itself or uses fake headers to elude detection. ![]()
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